HR: 1400h
AN: PP43C-09    [Abstracts]
TI: Comparison of new geochemical proxies in a stalagmite from sub tropical Mexico
AU: * Ernesto, H
EM: humancuantic@yahoo.com.mx
AF: Departamento de Geoquimica, Instituto de Geología, UNAM, Ciudad Universitaria, Mexico City, D.F 04510, Mexico
AU: Bernal, J
EM: jpbernal@geologia.unam.mx
AF: Departamento de Geoquimica, Instituto de Geología, UNAM, Ciudad Universitaria, Mexico City, D.F 04510, Mexico
AU: Lounejeva, E
EM: elenal@servidor.unam.mx
AF: Departamento de Geoquimica, Instituto de Geología, UNAM, Ciudad Universitaria, Mexico City, D.F 04510, Mexico
AU: McCulloch, M
EM: malcolm.mcculloch@anu.edu.au
AF: Research School of Earth Sciences, The Australian National Univeristy, ACTON, Canberra, ACT 0200, Mexico
AU: Morales, P
EM: pmorales@geologia.unam.mx
AF: Departamento de Geoquimica, Instituto de Geología, UNAM, Ciudad Universitaria, Mexico City, D.F 04510, Mexico
AU: Cienfuegos, E
EM: cienfuegos@servidor.unam.mx
AF: Departamento de Geoquimica, Instituto de Geología, UNAM, Ciudad Universitaria, Mexico City, D.F 04510, Mexico
AB: The mexican subtropics represent an interesting area to understand past climate change and variability since it is located within the current northern limit of the Inter Tropical Convergence Zone(ITCZ). Consequently, the area is very sensitive to changes in the average position of the ITCZ. We have collected a 33cm stalagmite from Cuetzalan, Pue. Mex (20°00'N, 97°32'W), that grew between 24.08 to 22.35 ky B.P. The stalagmite was analyzed for Sr/Ca, Ba/Ca, Mg/Ca, U/Ca molar ratios, δ¹³C, δ¹⁸O, [²³⁴U/²³⁸U], and other trace elements, and represents the first stalagmite record from tropical Mexico. Significant variations in the [²³⁴U/²³⁸U] in the stalagmite, suggest changes in the local weathering rates that are not reflected in other geochemical proxies. However, comparison of the E/Ca and δ¹⁸O with records from Hulu (China) and Botuvera (Brazil) caves suggest that the climate in the area was in line with the global climate system.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1635 Oceans (1616, 3305, 4215, 4513)
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
DE: 4215 Climate and interannual variability (1616, 1635, 3305, 3309, 4513)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Joint Assembly